Carburetor



Nov. 11, 1930. M. GOUDARD 1,781,575

CARBURETOR Filed July 1. 1929 Patented Nov. 11, 1930 "WE ZSTATES.

PATENT OFFICE f.

MAURICE eonDARn, or NEUILLY, FRANCE, AssIGnoR ro sooIETnANoNYMn soLnx,

or NEUILLY,'FR-ANCE, AsooIErY or FRANCE oARBUnEToR Application file-5.July 1, 1929, Serial No. araeai, andfin B-elgium August l, 192's.

, The present invention relates to carbtretors and, more particularly tothose of the type provided with a main and a slow speed nozzle.

. 5 In carburetors provided with'a main and a slow speed (oridling)nozzle, it has been a long standing problem to find means for tions asfollows:

bridging the gap in carburation existing between the period when thefeed from slow 1; speed nozzle ceases and the feed from the mainnozzle'begins.

One of the objects of the present invention is to provide an improvedform of carburetor in which the gap in carburation is elimi- '15 nated.

, 2.3 ings, there is shown a constant level reservoir 1 provided with afloat 2 controlling needle valve 8,-a fuelsupply conduit '4communicating with a fuel source (notshown), a fuel conduit 5,acalibrated passage 6,

, topped by a nozzle 7 which communicates through orifices 8 with a fuelwell 9 provided with an air-intake baffle 10,-a cylindrical mixingchamber 12 dividedinto airintake portion 11 and fuel outlet portion 13'5 by a butterfly valve pivotally mounted at16 and having two wingportions 14 and15,an auxiliary or slow-speed fuel 7 conduit ,17 inseries with orifices 8 and terminating in 'noz zle 18,an auxiliarymixing chamber 19 ter- =11) minating in the wall of mixing chamber .12

by an orifice 21 whose upstream' edge is slightly downstreamward of aplane passing through the center of axis 16 andat right angles to thelongitudinal axis of mixing a .5 chamber 12,--and a by-pass auxiliarymixing chamber 22 terminating in an orifice 23 positioned slightlyupstreamward with relas tion to valve wing-15when the latter is inclosed position. The butterfly valvejshould be positioned so that, inclosed position, the

upstreamedge of wing 14 covering orifice 21 corresponding downstreamedge of wing 14 covers orlficc 21 and hes downstreamward of the saidtransversep1ane; 7

The hereinabove described assembly func- Assuming the butterfly valvetobe-in the position shown in Fig. 1, a slight opening movement of: the,valve will cause the upstream and downstream edges of wing 14 cov-,ering orifice 21"to move away from the Wall 'ofmixing chamber 12byidifferent amounts, the upstream edge remaining substantially tangentto the wall (since. it lies in the transverse plane passing through thecenter of 16) while the "downstream edge moves away a relat velyconsiderable dlstance (since it lies above said transverse plane andhasa longer 7 radius) Otherwiseexpressed, thesection in cluded between saiddownstream edge and the mixing chamber will increase 'more rapidly, thanthecorresponding section limited bythe upstream edge andthemixingchamber wall as the valve'opens and the feed of fuel inixtureahrough orifice 21'rwill therefor at first increaseithen, whenthe'valve is'suflicient- 'iy open tobring nozzle 7 into action,decrease.

it is at this point that by-pass 22 controlled bywing le comes into playto'correctthe lag of nozzle 7, the opening movement of the? valveplacingorifices 23 on the suction side of. the butterfly valve and maintainingthe suctionon (andthe feed from) nozzle18 long enough to fill the gap incarburation that would otherwise'exist. It is to be understood,-

of course, that the sections of passages 19 and 22 must be properlychosen and orifices 21 and 23;positioned exactly as described to obtainthe result desired.

' WVhatI claim is 1. .A carburetor comprisinga main mixing chamberhaving. a cylindrical wall portion,

a main nozzle positioned to feed fuel to said main-mixing chamber,afirst' auxiliary mixing. chamber having a terminal orifice inthecy-lindricalportion of themain mixing chamberga second auxiliary mixingchamber havmg oneiextrern ty communicating with said first auxiliarymixing chamber and having a terminal orifice in the cylindrical portionof the main mixing chamber at a point upstreamward with relation to theterminal orifice of the first auxiliary mixing chamber, an auxiliarynozzle positioned to supply fuel to said first and second auxiliarymixing chambers, means for supplying fuel to said main and auxiliarynozzles, and an elliptical valve positioned to simultaneously obstructthe main mixingchamber and the terminal orifice of the first auxiliarymixing chamber, said valve, when in closed position,

sloping so that that portion thereof obstructing the terminal orifice ofthe first auxiliary mixing chamber lies downstreamward with relation tothe rest of the valve.

2. A carburetor comprising in combination a main mixing chamber having acylindrical wall portion, a main nozzle positioned to feed fuel to saidmain mixing chamber, a first auxiliary mixing chamber having a terminalorifice inthe cylindrical portion of the main specification.

MAURICE GOUDARD.

mixing chamber, a rotatable butterfly valve of elliptical outlinepositioned in the main mixing chamber so that, in closed position,

the edge of one wing thereof obstructs the a terminal orifice of thefirstauxiliary mixing chamber, said valve'sloping, when in closedposition, so that that portion thereof, ob.- structing the terminalorifice of the firstauxiliary mixing chamber, lies downstreamward withrelation to the rest of the valve, a second auxiliary mixing chambercommunicating at one extremity with the first auxiliarymixing chamberand having a terminal orificein themain mixing chamber at a pointupstreamward of that wing of the butterfly valveopposite the onecontrolling the ter- -minal orificelof the first auxiliary mixingchamberwhen said wings are 1n closed position, an auxiliary nozzlepositloned to feed fuel to said first and second auxiliary mixingchambers,.and means for supplying fuel to the main and auxiliarynozzles.

3. A carburetor comprising a main mixing chamber having a cylindricalWall portion,

a main nozzle positioned to supply fuel to said main mixing. chamber, afirst auxiliary niixingvchamber having a'terrfiinal orifice in the-cylindrical portion of said main mixing'chamber, a rotatable, butterflyvalve of ellipticaloutline positionedin the main mixingch'amber so that,in closed position, the

iliary mixing chamber, saidvalve having its axis positioned so that aplane therethrough' perpendicular tothe longitudinal axis of the inai-nmixing chamber passes susbstantially throughthe upstream edge of theterminal orifice of the first auxiliary mixing-chamber,

a second, auxiliaryrmixing' chamber having 1 one extremity communicatingwith the first I auxiliary mixing chamber andhaving a teredgeof onewilng'ofsaid butterfly valve ob l 5 structs the tcrminalorifice of thefirst'aux-

